Parsed test spec with 3 sessions

starting permutation: s2_delete s1_group s3_pins s3_vacuum s2_reuse s1_rest s1_check
step s2_delete: DELETE FROM cpv WHERE c = 1 AND id <= 2000;
step s1_group: 
	BEGIN ISOLATION LEVEL REPEATABLE READ;
	DECLARE cpv_cur CURSOR FOR SELECT g, count(*) FROM cpv WHERE c = 1 GROUP BY g;
	SELECT cpv_take(1) AS first;

first
-----
    1
(1 row)

step s3_pins: 
	SELECT count(*) AS lion_pages_pinned FROM pg_buffercache
	 WHERE reldatabase = (SELECT oid FROM pg_database WHERE datname = current_database())
	   AND relfilenode IN (pg_relation_filenode('cpv_g'), pg_relation_filenode('cpv_c'))
	   AND pinning_backends > 0;

lion_pages_pinned
-----------------
                0
(1 row)

step s3_vacuum: VACUUM (INDEX_CLEANUP ON) cpv;
step s2_reuse: INSERT INTO cpv SELECT 10000 + i, i % 4, 1 FROM generate_series(1, 2000) i;
step s1_rest: SELECT cpv_take(NULL) AS rest;
rest
----
   1
(1 row)

step s1_check: 
	SET LOCAL enable_seqscan = on;
	SET LOCAL pg_lion.enable_count_pushdown = off;
	SELECT (SELECT count(*) FROM cpv_got) AS groups,
		   (SELECT count(*) FROM
			((SELECT g, n FROM cpv_got
			  EXCEPT ALL SELECT g, count(*) FROM cpv WHERE c = 1 GROUP BY g)
			 UNION ALL
			 (SELECT g, count(*) FROM cpv WHERE c = 1 GROUP BY g
			  EXCEPT ALL SELECT g, n FROM cpv_got)) d) AS wrong;
	COMMIT;

groups|wrong
------+-----
     2|    0
(1 row)


starting permutation: s2_delete s1_count s3_pins s3_vacuum s1_commit
step s2_delete: DELETE FROM cpv WHERE c = 1 AND id <= 2000;
step s1_count: 
	BEGIN ISOLATION LEVEL REPEATABLE READ;
	DECLARE cpv_cnt CURSOR FOR SELECT count(*) FROM cpv WHERE c = 1 AND g = 1;
	FETCH 1 FROM cpv_cnt;

count
-----
  100
(1 row)

step s3_pins: 
	SELECT count(*) AS lion_pages_pinned FROM pg_buffercache
	 WHERE reldatabase = (SELECT oid FROM pg_database WHERE datname = current_database())
	   AND relfilenode IN (pg_relation_filenode('cpv_g'), pg_relation_filenode('cpv_c'))
	   AND pinning_backends > 0;

lion_pages_pinned
-----------------
                0
(1 row)

step s3_vacuum: VACUUM (INDEX_CLEANUP ON) cpv;
step s1_commit: COMMIT;